Common testing module

Now that we have a lot of modules to deal with, it becomes tedious to configure the imports and providers for each spec file individually. For this purpose, create a common testing module to contain a generic configuration that you can reuse across the board.

First, start by creating a new .ts file:

1. Create common/common.testing.ts.
2. Populate it with common testing providers, fakes, and modules.

I have provided a commonTestingModules array:

src/app/common/common.testing.ts
import {
  HttpClientTestingModule
} from '@angular/common/http/testing'
import { ReactiveFormsModule } from '@angular/forms'
import {
  NoopAnimationsModule
} from '@angular/platform-browser/animations'
import { RouterTestingModule } from '@angular/router/testing'
import {
  MatIconTestingModule
} from '@angular/material/icon/testing'
export const commonTestingProviders = [
  // Intentionally left blank! Used...